When a display is exposed to external light such as various illumination and natural light, an image formed inside the display is not clearly focused on an eye, thereby causing deterioration in contrast of the display. Due to such deterioration in contrast, a person has a difficulty in viewing a screen and suffers from eye fatigue or a headache. For this reason, there is a strong demand for anti-reflection.
As the need for anti-reflection has been emphasized, in an effort to find a film structure capable of providing anti-reflection in the visible range, an anti-reflective film including a high refractive-index layer and a low refractive-index layer repeatedly stacked one above another has been developed, and continuous studies have been made to reduce the number of layers. Such an anti-reflective film has been developed in the form of a stack structure in which a low refractive-index layer is formed on a high refractive-index layer. In addition, it has been found that anti-reflection effects increase with increasing difference in index of refraction between the low refractive-index layer and the high refractive-index layer. However, it is still challenging to design an anti-reflective film including a low refractive-index layer and a high refractive-index layer.